KR20020000379A - Flat type-vibration motor - Google Patents

Abstract

PURPOSE: A flat vibration motor is provided to enhance the number of rotations and vibration characteristics by arranging an auxiliary magnet on an upper case. CONSTITUTION: A flat vibration motor(1) includes upper and lower cases(10,20), a shaft(15) inserted into the upper and lower cases(10,20), an eccentric rotor(30) eccentrically supported on an external part of the shaft(15), and a magnetic force generating unit fixed on an inside surface of the upper and lower cases(10,20) around a center of the eccentric rotor(30). A flange is formed on the upper and lower cases(10,20) to axially fix both ends of the shaft(15) at the center of the inside surface. A substrate(21) is attached on an upper surface of the lower case(20). An end of a pair of brushes(23) is fixed to the substrate(21) and upper end of the brushes(23) upwardly extends toward the eccentric rotor(30). The shaft(15) is a fixed shaft for allowing the eccentric rotor(30) to rotate. Both ends of the shaft are fixed to the flanges of the upper and lower cases. A bearing is inserted on an end of the center of the shaft(15). A shaft hole is formed on a side section of the eccentric rotor(30), and the bearing is inserted into the shaft hole, so that the eccentric rotor rotates about the shaft(15).

Description

Flat vibration motor {Flat type-vibration motor}

The present invention relates to a flat vibration motor mounted on a small electronic device to exhibit vibration characteristics, and more particularly, to flatten a magnetic flux efficiently to block leakage magnetic flux and at the same time to increase torque of a motor. It's about a motor.

In general, the flat vibration motor is a vibration is generated in the process of rotating around the shaft in a state that the rotor is eccentric, it is usually manufactured in a small size and used in the electronic products that require vibration, these flat vibration motor has been recently used For example, the demand is increasing explosively as being used as a silent call (silent call) means of the mobile communication terminal.

Such a conventional flat vibration motor has a lower case 120 having a shaft 115 fixed to the center at the bottom thereof, as shown in the cross-sectional view of FIG. 1, and the lower case 120 has a substrate 121 on the upper surface thereof. The magnet 122, which is magnetized into a plurality of poles, is fixedly seated on the substrate 121.

In particular, the inner circumferential surface of the magnet 122 has a pair of brushes 123 located at a predetermined angle spaced apart from the upper surface of the magnet 122 while the lower end is magnetized to the substrate 121.

In addition, an eccentric rotor 130, in which a semicircular insulating resin body 131 ′ is integrally formed to be eccentric from the shaft 115, is pivotally supported on the shaft 115 at an upper portion of the brush 123.

The eccentric rotor 130 is provided with a plurality of armature coil 131 on one side, the previous magnetic coil 131 is a power source of different polarity by the printed circuit board 132 attached to the bottom of the eccentric rotor 130 Is supplied.

The printed circuit board 132 is supplied with power from the commutator 133 attached to the bottom, and the power supplied from the commutator 133 is an eccentric rotor through a pattern formed on the upper and lower surfaces of the printed circuit board 132. Different power is supplied to at least one pair of armature coils 131 of the plurality of armature coils 131 provided at 130.

On the other hand, the commutator 133 is a circular connection terminal attached to the bottom surface of the printed circuit board 132, such that the connection terminal is divided into a plurality of evenly spaced minute intervals so that a pair of segments corresponding to each other have the same polarity Therefore, two pairs of segments having corresponding polarities have different polarities while the other pair of segments have no polarity.

Finally, the rotor 130 is axially supported on the upper portion is coupled to be seated on the outer periphery of the lower case 120 and the inner surface is spaced apart from the upper surface of the eccentric rotor 130 of the rotor 130 at a predetermined interval (shaft ( The upper case 110 supporting the upper surface of the 115 is covered and assembled.

When the flat vibration motor 100 configured as described above is supplied with power from the outside to the substrate 121, each of the flat vibration motors 100 leads to current having different polarities through a pair of brushes 123 attached to the center of the substrate 121. Thus, power is supplied to a pair of armature coils 131 of the eccentric rotor 130 along a pattern of the printed circuit board 132 through a pair of segments having different polarities among the segments of the commutator 133.

Subsequently, the eccentric rotor 130 is rotated in one direction by the electromagnetic force generated by the interaction between the flow direction of the current induced in the armature coil 131 and the magnet 122, wherein the eccentric rotor 130 is rotated Each time the contact segments with the commutator 133 by the brush 123 is changed, the polarity of the power is continuously changed, so that the eccentric rotor 130 combined with the printed circuit board 132 and the commutator 133 continuously rotates. You can do it.

Therefore, since the eccentric rotor 130 is eccentric shaft support with respect to the shaft 115, because the weight is rotated in a biased state will cause vibration.

However, the conventional flat vibration motor 100 has a problem in that the vibration characteristics of the vibration motor 100 are also weakened as the electronic products such as mobile communication terminals are aimed at miniaturization and light weight.

That is, the magnetic flux characteristics between the eccentric rotor 130 and the magnet 122 are weakened as the size of the magnet 122 configured in the vibration motor 100 becomes smaller, so that the eccentric rotor 130 smoothly rotates in this state. A problem arises that cannot be achieved.

This problem can be solved by reducing the amount of eccentricity of the eccentric rotor 130, that is, by reducing the load that the eccentric rotor 130 puts on the shaft 115, but as a result, the eccentric rotor 130 becomes lighter, so that the vibration motor Another problem is that the vibration force, which is a characteristic, becomes weak.

The present invention was created in order to solve the above-described problems, and an object of the present invention is to provide an auxiliary magnet in the upper case to increase magnetic flux concentration while suppressing leakage flux between the eccentric rotor and the magnet magnetized in the lower case. The purpose is to provide a flat vibration motor that can increase the rotational speed and vibration characteristics of the vibration motor according to the thinning.

1 is a cross-sectional view showing a flat vibration motor according to the prior art,

2 is a cross-sectional view showing a flat vibration motor according to the present invention;

3 is an exploded perspective view of a flat vibration motor according to the present invention;

4 is a cross-sectional view showing another embodiment of a flat vibration motor according to the present invention.

<Description of the symbols for the main parts of the drawings>

1: Vibration motor 10: Upper case

12: auxiliary magnet 15: shaft

16: bearing 20: lower case

21: substrate 22: magnet

23 brush 30 eccentric rotor

31: electric coil 32: printed circuit board

33: commutator

Flat vibration motor according to the present invention for achieving the above object is a lower case having a substrate on which magnets and brushes are magnetized on the upper surface;

An upper case coupled to the lower case to form a space portion of a predetermined size therein;

Shafts are fixed at both ends in the center of the inner surface of the upper and lower cases,

An eccentric rotor supported by a shaft on the shaft and wound on an upper surface of an armature coil wrapped with an insulator, and a lower surface of which is mounted a printed circuit board having a commutator in contact with a brush;

It is provided on the flat portion of the upper case characterized in that it comprises an auxiliary magnet for inducing a magnetic force line of the magnet.

Hereinafter, a flat vibration motor according to the present invention will be described with reference to the accompanying drawings.

2 is a cross-sectional view showing a flat vibration motor according to the present invention, Figure 3 is an exploded perspective view of the flat vibration motor according to the present invention.

And, Figure 4 is a cross-sectional view showing another embodiment of a flat vibration motor to which the present invention is applied.

The flat vibration motor 1 of the present invention is the upper, lower case 10, 20 coupled to the cylindrical shape, and the shaft 15 placed inside the upper, lower case 10, 20 and The eccentric rotor 30 which is eccentrically axially supported on the outer circumference of the shaft 15 and the magnetic force is fixedly seated on the inner surfaces of the upper, lower cases 10, 20 around the eccentric rotor 30 respectively. Means.

The upper case 10 and the lower case 20 have a flange for axially fixing both ends of the shaft 15 in the center of the inner surface, in particular, the substrate 21 is attached to the upper surface of the lower case 20. Then, one end is fixed on the substrate 21 and the upper end is provided with a pair of brushes 23 extending upward toward the eccentric rotor 30 side.

The shaft 15 is a kind of fixed shaft that allows the eccentric rotor 30 to be rotated. Both ends of the shaft 15 are fixed to the flanges of the upper and lower cases 10 and 20, respectively, and the bearing 16 is fitted to one end of the shaft 15. Lose.

The eccentric rotor 30 has a shaft hole formed on one side, and the shaft 16 is inserted into a bearing 16 coupled to the outer circumference of the shaft 15 so that the eccentric rotor 30 has a shaft ( 15) is configured to rotate about.

In the eccentric rotor 30, a plurality of armature coils 31 wrapped with an insulating resin 31 ′ are provided on an upper surface thereof, and a printed circuit having a commutator 33 contacting a pair of brushes 23 on a bottom surface thereof. The substrate 32 is attached.

The magnetic force generating means generates the electromagnetic force by the interaction with the above-described eccentric rotor 30 and is magnetized to the lower case 20 and the upper case 10, respectively.

The magnetic force generating means is substantially divided into a magnet 22 provided in the lower case 20 and an auxiliary magnet 12 provided in the upper case 10 as having the characteristic elements of the present invention.

The magnet 22 provided in the lower case 20 is magnetized to a plurality of poles on the upper surface of the substrate 21 as before, and is arranged and fixed around the shaft 15.

The auxiliary magnet 12 provided in the upper case 10 is magnetized to a corresponding pole so as to induce interaction with the magnet 22 provided in the substrate 21.

That is, when the magnet 22 of the lower case 20 is the N pole, the auxiliary magnet 12 of the upper case 10 has the polarity of the S pole, and when the magnet 22 of the lower case 20 is the S pole, the upper case The auxiliary magnet 12 of the case 10 has a polarity of the N pole, and has a polarity corresponding to each other so that a predetermined magnetic force is applied between the auxiliary magnet 12 and the magnet 22.

Here, the upper case 10 has a predetermined size in a flat portion corresponding to an upper portion of the magnet 22 provided on the substrate 21 of the lower case 20 in order to facilitate the configuration of the auxiliary magnet 12. An installation hole 11 is formed, and the auxiliary magnet 12 may be manufactured and fitted into a size corresponding to the size of the installation hole 11 and then coupled through an adhesive or the like.

Referring to the operation of the flat vibration motor according to the present invention made as described above are as follows.

When the power supplied from the outside is supplied to the substrate 21, the pair of brushes 23 attached to the center portion of the substrate 21 are induced with currents of different polarities, and these currents are in contact with the brushes 23. The commutator 33 is applied to the armature coil 31 of the printed circuit board 32.

Subsequently, an electromagnetic force is generated by the interaction between the flow direction of the current induced in the armature coil 31 and the magnetic force generating means, and the eccentric rotor 30 rotates about the shaft 15 by the electromagnetic force.

Therefore, since the eccentric rotor 30 is eccentrically supported with respect to the shaft 15, that is, it rotates in a state where the weight is biased, it causes vibration.

Here, the eccentric rotor 30 is obtained by the magnetic force generating means further improved rotational force and the number of rotations, which is the magnet 22 and the auxiliary magnet 12, the magnetic force generating means is the lower case 20 and This is because the magnetic flux is concentrated in the eccentric rotor 30 by the interaction of the magnets with polarities corresponding to the upper case 10.

That is, the magnetic force of the magnet 22 of the lower case 20 is induced to proceed in the upward direction by the auxiliary magnet 12 provided in the upper case 10, the magnetic flux received by the eccentric rotor 30 is Compared with the past, the leakage magnetic flux of the magnet 22 is suppressed.

Therefore, since the eccentric rotor 30 receives a strong magnetic flux from the magnet 22, it is possible to obtain a more powerful rotational speed and rotational force around the shaft 15, thus reducing the eccentric amount of the eccentric rotor 30 If it is made larger, greater vibration can be expected.

The flat vibration motor according to the present invention constructed and operated as described above provides an auxiliary magnet having a polarity corresponding to the magnet magnetized in the lower case in the upper case, thereby inducing the magnetic force lines of the magnet to be concentrated upwards. The leakage of the magnetic flux can be suppressed.

Therefore, the magnetic flux characteristic between the magnet and the eccentric rotor is strengthened, that is, the energy in the air gap can be utilized to the maximum, so that the rotational force of the eccentric rotor can be further improved, and in particular, the amount of eccentricity can be increased according to the rotational force of the eccentric rotor. Therefore, there is an advantage that can strengthen the vibration strength.

Therefore, the flat vibration motor according to the present invention can be expected to reduce the rated current and increase the minimum starting voltage according to the increase in the rotational force and the rotational speed, and in particular, the design freedom of the product can be further increased. There is an advantage that can further accelerate the downsizing.

Claims (3)

A lower case having a substrate on which magnets and brushes are magnetized on an upper surface thereof; An upper case coupled to the lower case to form a space portion of a predetermined size therein; Shafts each having both ends fixed to a center of an inner surface of the upper and lower cases; An eccentric rotor axially supported by a bearing on the shaft and wound on an upper surface of the armature coil wrapped with an insulator, and attached to a lower surface thereof with a printed circuit board having a commutator in contact with a brush; Flat vibration motor provided in the flat portion of the upper case comprising a secondary magnet for inducing a magnetic force line of the magnet. The method of claim 1, The auxiliary magnet has a flat vibration motor, characterized in that it has a polarity corresponding to the magnet magnetized on the substrate of the lower case The method of claim 1, The upper case is a flat vibration motor, characterized in that a predetermined installation hole is formed in the flat portion located in a direction opposite to the magnet, the plate-shaped auxiliary magnet is coupled to this hole.